Ti₃C₂T_x MXene Nanosheets as a Robust and Conductive Tight on Si Anodes Significantly Enhance Electrochemical Lithium Storage Performance

Abstract

Exploring Si-based anode materials with high electrical conductivity and electrode stability is crucial for high-performance lithium-ion batteries (LIBs). Herein, we propose the fabrication of a Si-based composite where Si porous nanospheres (Si p-NSs) are tightly wrapped by Ti 3 C 2 T x (T x stands for the surface groups such as −OH, −F) MXene nanosheets (TNSs) through an interfacial assembly strategy. The TNSs as a conductive and robust tight of the Si p-NSs can effectively improve electron transport and electrode stability, as revealed by substantial characterizations and mechanical simulations. Moreover, the TNSs with rich surface groups enable strong interfacial interactions with the Si p-NS component and a pseudocapacitive behavior, beneficial for fast and stable lithium storage. Consequently, the Si p-NS@TNSs electrode with a high Si content of 85.6% exhibits significantly enhanced battery performance compared with the Si p-NSs electrode such as high reversible capacity (1154 mAh g −1 at 0.2 A g −1 ), long cycling stability (up to 2000 cycles with a 0.026% capacity decay rate per cycle), and excellent rate performances. Notably, the Si p-NS@TNSs electrode-based LIB full cell delivers a high energy uptake of 405 Wh kg −1 , many-times higher than that of the Si p-NSs full cell. This work offers a strategy to develop advanced Si-based anode materials with desirable properties for high-performance LIBs.

Double transition metal MXene (TixTa4−xC3) 2D materials as anodes for Li-ion batteries

“…This unique sandwich morphology can relieve the strain of the electrode on cycling and deliver an enhanced carrier transport mechanism to prevent aggregation of active material. Xia et al 58 used an interfacial assembly strategy to assemble Si porous nanospheres on titanium carbide MXene sheets; improving the electrode's electron transport and stability. The MXene surface groups enable strong interaction with Si porous nanoparticles and develop pseudocapacitive behaviour, which can be advantageous for Li-ion storage.…”

N-doped porous carbon nanofibers sheathed pumpkin-like Si/C composites as free-standing anodes for lithium-ion batteries

“…To date, lithium-ion batteries (LIBs) have been widely used in advanced mobile electric vehicles (EVs) and portable electronics because of their high energy density and long lifecycle [1][2][3][4][5][6][7][8][9][10]. However, the capacity of traditional graphite anodes (372 mA h g À1 ) cannot meet the requirement of LIBs for higher energy density [11,12]. Among the existing candidates, Si anodes have been regarded as the most promising alternative to graphite for LIBs ascribing to the abundant natural resources, low discharge potential (~0.4 V versus Li/Li + ), and high theoretical specific capacity (~3579 mA h g À1 Li 15 Si 4 ) [13][14][15].…”

Challenges and Recent Progress on Silicon‐Based Anode Materials for Next‐Generation Lithium‐Ion Batteries

“…Except for choosing the flexible materials with Si‐based anode, the designed structure of Si‐based anodes also usually combine with MXene, [ 33,34 ] TiN, [ 35 ] metal oxide, [ 36 ] Cu x Si y , [ 37 ] SiO x , [18b,22,28b,38] Li x Si, [ 39 ] Ni–Sn, [ 40 ] Si 3 N 4 , [ 41 ] SiC, [ 42 ] Li 4 Ti 5 O 12 , [ 43 ] ZnO, [ 44 ] zeolitic imidazolate frameworks, [ 45 ] liquid metal, [ 46 ] sulfur fusion yields quasimetallic, [ 47 ] etc. These rigid materials could weaken the expansion of volume while electrode reaction, improve the electrical conductivity and electrode stability of anodes.…”